An Iowa man set up a hidden video camera disguised as an alarm clock to record a woman and her two children as they used the bathroom and shower in their Ankeny home, authorities said.

Brian Gerard Hoffman, 53, of Lidderdale, was arrested Wednesday on two counts of sexual exploitation of a minor and one count of invasion of privacy and unlawful interception of communication, court documents show.

A woman called police in December to report that Hoffman, one of her friends, had placed the hidden camera disguised as an alarm clock in her home in the 1800 block of SE Greenpark Circle, authorities said.

The clock, which had a 16-gigabyte memory card and was accessible through a wireless internet connection, faced her bathroom and recorded her and her children, ages 11 and 12, naked, according to court records. The memory card had multiple video and audio recordings, police said.

Hoffman told officers he placed the clock in the woman's residence, but he did not know it was a recording device. He also told police he used her Wi-Fi to set up the clock, officers wrote in a criminal complaint.

In court records, police said "it was apparent" Hoffman knew the clock was a recording device.